The Magnetic Mechanics Behind New Therapy Research

Nanoparticles are a promising treatment option for cancers that are resistant to common therapies. In a new study that demonstrates an innovative and non-invasive approach to cancer treatment, Northwestern Medicine scientists successfully used magnetic nanoparticles to damage tumor cells in animal models.

“What distinguishes these nanoparticles from others is that they have a magnetic dipole, a property that allows them to rotate along the axis,” explained Matt Lesniak, MD, a neurological oncologist and the Michael J. Marchese professor and chair of Neurological Surgery at Northwestern University Feinberg School of Medicine. “When we apply a magnetic field externally, these nanoparticles spin. We made the nanoparticles attach to the surfaces of cancer cells and then induced the spinning to mechanically destroy the cell membranes.

“Most cancer therapies – chemotherapy, radiation – focus on DNA damage, which cancer cells often find a way to overcome,” Dr. Lesniak continued. “Using mechanical force is a very different way of thinking about cancer treatment.”

Unlike other nanoparticles that rely on heat, light or chemicals to work against cancer, the magnetic particles were designed so they would not impair normal cells in the process. To make sure they can target cancer cells, the particles can be equipped with an antibody that recognizes a receptor expressed only on cancer cells.

The scientists injected the nanoparticles into the brain and applied a low frequency, rotating magnetic field. The spinning nanoparticles created enough force to damage cancer cell membranes and jump-start cell death in brain tumors. The method reduced tumor size and prolonged the survival rate of mice, without adverse affects.

“I think this has applications to many types of cancers, from brain tumors to breast cancer,” said Dr. Lesniak. “As long as there’s a specific target, you can take advantage of the nanoparticle’s mechanical properties.”

Before the strategy can be tested in humans, the scientists need to determine appropriate dosing for the nanoparticles, a challenge that will require mathematical modeling to understand the logarithmic growth of cancer cells. Future research also needs to explain how the particles clear from the brain.

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